Department of Food Science and TechnologyTheses, Dissertations and Student Research Papers (Food Science and Technology)http://hdl.handle.net/1957/178812015-03-24T16:32:39Z2015-03-24T16:32:39ZEffects of Different Organic Weed Management Strategies on the Physicochemical, Sensory, and Antioxidant Properties of Machine-Harvested Blackberry FruitsCavender, GeorgeLiu, MingyangHobbs, DeborahFrei, BalzStrik, BernadineZhao, Yanyunhttp://hdl.handle.net/1957/553042015-03-13T00:32:38Z2014-10-01T00:00:00ZEffects of Different Organic Weed Management Strategies on the Physicochemical, Sensory, and Antioxidant Properties of Machine-Harvested Blackberry Fruits
Cavender, George; Liu, Mingyang; Hobbs, Deborah; Frei, Balz; Strik, Bernadine; Zhao, Yanyun
The effect of three different weed management strategies, non-weeding, hand weeding, and weed mat, were examined on physicochemical, sugar profile, and antioxidant properties of two cultivars of blackberry (Rubus spp), ’Marion’ and ’Black Diamond’ harvested at three time intervals during the 2012 season. Sensory analysis on flavor intensity of six different descriptors by an experienced panel was also performed on ‘Black Diamond’ berries harvested at the same interval during the 2013 season. While weed management had no effect on pH, titratable acidity and total soluble solids of either cultivar (P>0.05), it showed a marked effect on total phenolics (5.65-7.80 mg GAE/g FW), total monomeric anthocyanins (1.07-2.85 mg/g FW), ORAC (271.51-644.97 μMol TE/g FW), FRAP (408.56-719.10 μMol Fe²⁺/g FW), sugar profile, and flavor intensity. Hand-weeding resulted in fruit antioxidant content and capacity as much as 30% greater, though the effect was not seen in the late harvest, where the non-weeded samples tended to have higher values. Overall, weed mat samples had the lowest antioxidant content and capacity in all harvests. Sugar profiling exhibited a greater variability based on cultivar and harvest, but overall, weed mat samples had lower sugar levels than fruit from the other two methods. Interestingly, the intensity of sensory attributes for ’Black Diamond’ appear to possibly be inversely related to phenolic and anthocyanin content, with the weed mat management strategy resulting in the highest values for virtually all sensory attributes. This study provided valuable information about the impact of organic production method on the quality of blackberries.
This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by the Institute of Food Technologists and published by John Wiley & Sons, Inc. It can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291750-3841
2014-10-01T00:00:00ZOptimized production of Serratia marcescens B742 mutants for preparing chitin from shrimp shells powdersZhang, HongcaiFang, JiyangDeng, YunZhao, Yanyunhttp://hdl.handle.net/1957/541882014-11-24T22:14:24Z2014-08-01T00:00:00ZOptimized production of Serratia marcescens B742 mutants for preparing chitin from shrimp shells powders
Zhang, Hongcai; Fang, Jiyang; Deng, Yun; Zhao, Yanyun
To improve the deproteinization (DP) efficacy of shrimp shell powders (SSP) for preparing chitin, Serratia marcescens B742 mutants were prepared using 2% diethyl sulfate (DES), UV-irradiation, and/or microwave heating treatments. Both single-stage and multi-stage mutations were investigated for optimizing S. marcescens B742 mutation conditions. Under the optimized mutation conditions (2% DES treatment for 30 min plus successive 20 min UV-irradiation), the protease and chitosanase activity produced by mutant S. marcescens B742 was 240.15 and 170.6 mU/mL, respectively, as compared with 212.58 ± 1.51 and 83.75 ± 6.51 mU/mL, respectively, by wild S. marcescens B742. DP efficacy of SSP by mutant S. marcescens B742 reached 91.4 ± 4.6% after 3 d of submerged fermentation instead of 83.4 ± 4.7% from the wild S. marcescens B742 after 4 d of submerged fermentation. Molecular mass of chitosanase and protease was 41.20 and 47.10 kDa, respectively, and both enzymes were verified by mass spectrometry analysis. The chitosanase from both wild and mutant S. marcescens B742 was activated by sodium dodecyl sulfate (SDS), Tween 20, Tween 40, and Triton-100, and the protease and chitosanase were strongly inhibited by ethylenediaminetetraacetic acid (EDTA). These results suggested that S. marcescens B742 mutants can be used in the biological production of chitin through deproteinization of SSP.
This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/international-journal-of-biological-macromolecules/
2014-08-01T00:00:00ZImpact of High Pressure Processing on the Functional Aspects of Beef Muscle Injected with Salt and/or Sodium PhosphatesLowder, Austin C.Dewitt, Christina A. Mireleshttp://hdl.handle.net/1957/539052014-11-17T16:01:14Z2013-10-09T00:00:00ZImpact of High Pressure Processing on the Functional Aspects of Beef Muscle Injected with Salt and/or Sodium Phosphates
Lowder, Austin C.; Dewitt, Christina A. Mireles
This study aimed to determine the interactions 31 among salt (NaCl), sodium phosphate
(SP) and mild HPP in brine-injected beef. Beef strip loin segments were injected to 10% over initial weight with solutions containing water and various levels of salt (0, 2 or 4% of solution)
and/or SP (0 or 4% of solution). Pieces from the loin sections were exposed to varying pressure
levels (0.1, 152 or 303 MPa) and evaluated for selected quality and biochemical characteristics.
Use of SP and pressure application increased pH by ~0.2 units. L* values were increased by
pressure and decreased by SP. Redness (a*) increased at 303 MPa. Purge increases due to
pressure were mitigated by SP. Pressure application at 303 MPa reduced total and sarcoplasmic
protein solubility by 24 and 32%, respectively. There were no beneficial interactions among salt or SP and HPP. However, results indicate SP may prevent yield loss due to HPP.
This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by John Wiley & Sons Ltd. and can be found at: http://onlinelibrary.wiley.com/journal/10.1111/%28ISSN%291745-4549.
2013-10-09T00:00:00ZGelling properties of surimi as affected by the particle size of fish boneYin, TaoReed, Zachary H.Park, Jae W.http://hdl.handle.net/1957/526752014-10-03T23:21:42Z2014-10-01T00:00:00ZGelling properties of surimi as affected by the particle size of fish bone
Yin, Tao; Reed, Zachary H.; Park, Jae W.
The effects of fish bone with two different particle sizes (micro and nano) on Alaska pollock surimi gels prepared by two heating procedures were investigated. Heating procedures (with or without setting) resulted in significantly different gel texture values. Nano-scaled fish bone (NFB) effectively increased gel breaking force and penetration distance (up to 1 g/100 g) while micro-scaled fish bone (MFB) did not. Endogenous transglutaminase (TGase) activity of surimi paste increased obviously as the concentration of NFB increased, indicating calcium ions readily released from NFB and assisting gel formation through TGase-induced covalent bonds. With MFB, TGase activity increased slightly, but not significantly. Scanning electron microscopy (SEM) results revealed NFB was capable of being imbedded in the gel matrices without disrupting the myofibrillar gel network. Surimi with MFB formed a discontinuous and porous network with pores near the size of MFB. Lightness (L*) and whiteness (L*-3b*) of NFB gels were higher than those of MFB.
This is an author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/lwt-food-science-and-technology/.
2014-10-01T00:00:00Z